1. Field of the Invention
The present invention relates to sampler valves. More particularly, the present invention would relate to a sampler valve set perpendicular within a flow line to sample a specified amount of homogeneous fluid flowing within the line.
2. General Background
In the operation of chemical process plants or the like, or in the start-up of such plants, it is imperative that the materials used in the chemical processes be of the proper purity and strength as required in the processes. One means of assuring that this is accomplished is to take periodic samples of various chemical components utilized in the plant, and to run tests to assure that they are in line with the standards as established for the effectiveness within the plant.
In the case of homogeneous fluids which must be chemically intermixed or reacted to carry on the processes, the most effective means of establishing the purity of the flow within the line is to obtain a sample of the fluid within the line during the flow, so that a representative sample of the fluid within the line is obtained.
Obtaining reliably representative samples on a routine basis from chemical plant process streams is a long standing problem of the industry. Various solutions to eliminate specific sampling problems of difficult to handle process stream have been successfully approached but little or no attention has been devoted to insure accurate sampling of homogeneous liquid.
Accurate reliable sampling can save thousand of dollars daily during start up, shutdown and continuous operations. Repeat sampling to ensure reliability of the samples taken can be completely avoided by utilizing a minimum volume apparatus.
Typical sample systems are normally comprised of a common gate or globe valve 1/2" to 1" in diameter with the associated pipe nipples for connection to the process piping. The valves usually serve the purpose of draining lines and sampling is a convenient secondary use.
One major problem associated with this system is the large internal volume which requires one to two gallons of flushing to remove old material trapped in the pipes and valves. Even flushing large volumes of material does not insure complete purging of dead zones, or no flow areas in the sampling system. Therefore, sample reliability is always suspect. In addition, valve packings, O-rings, and gaskets also adsorb organic chemicals which also make samples suspect especially where trace analysis is required. Standard valves generally have periodic re-occurring leak problems which are not addressed in the present state of the art.
There are several patents which teach the use of sampler valves in various operations, the most pertinent being as follows:
U.S. Pat. No. 2,012,836 issued to Talbet et al entitled "Sampling Device" would teach the use of a device which is suited for sampling the waxy oil stream through pipe lines, generally comprising an open cup portion within the housing adapted to hold a continuously changing sample of liquid, and a conduit which leads into the cup projecting through the wall of the housing for gravitating the liquid from the cup. There is further provided a valving mechanism for controlling the gravitation of the liquid therefrom.
U.S. Pat. No. 3,260,120 issued to D. W. Stillwell entitled "Sampling Device" would teach the use of an apparatus for sampling from a stream during the sampling process. This particular apparatus is adapted especially for sampling polyolefin pellets with the according structure thereof.
U.S. Pat. No. 3,747,411 issued to McDermitt et al entitled "Suspension Sampling" would teach the use of a sampling apparatus designed for taking at regularly timed intervals samples of slurries as they are passed through a pipe line. In this particular apparatus, there is provided the insertion of a sampling tube into the pipe for removal of the portion.
U.S. Pat. No. 631,549 issued to F. Talcott and F. J. Daubenberger entitled "Milk Sampler" would teach the use of a sampling apparatus for sampling milk.
U.S. Pat. No. 3,267,735 issued to M. L. Fickle entitled "Fluid Sampling Valve" would teach the use of a rotative disc bleeder valve having a valve seat discharge passage threaded section and an enlarged section and an operating shaft for rotatably mounting the plug for allowing bleeding fluid therethrough.
U.S. Pat. No. 3,476,138 issued to Doremus, et al, entitled "Valve With Stop And Washout" relates to a valve for dispensing fluids, such as beer from a keg. The main function of this valve is to provide a washout slot so that the keg can be readily cleaned. There is provided a stop mechanism for the rotatable valve member, the slot also serving to wash out an extension member located on the valve body. This valve does not address the use of the valve for sampling homogeneous high pressure corrosive fluids.
Russian Pat. No. 397,803 issued to Tomacob shows the use of a pipe line liquid sampler using a perforated tube mounted perpendicular to the flow axis for averaging the samples. However, it should be noted, as seen in the drawings, that the perforations for the sampling tube receive the flow directly, and therefore do not necessarily receive a homogeneous sample. The port for receiving the flow within the present apparatus is perpendicular to the flow. In addition, the same structure is not taught in this particular patent.